Mammography apparatus

ABSTRACT

A mammography apparatus includes a detector that detects X-rays transmitted through a breast, and an optically transparent or semitransparent pressing panel for pressing the breast. The apparatus further includes a near infrared ray source that provided between the X-ray source and the pressing panel and arranged in a two-dimensional shape in alignment with the pressing panel, and that is movable between a first position in close contact with the pressing panel and a second position outside an X-ray image capture region. Near infrared image capture is carried out using the near infrared ray source by causing the near infrared ray source to be in the first position, and the near infrared ray source is caused to retract to the second position when carrying out X-ray image capture using the X-ray source.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to mammography apparatuses that obtainX-ray images of mammary specimens using X-ray imaging.

2. Description of the Related Art

Mammography apparatuses that obtain X-ray images of mammary specimensusing X-ray imaging include mammography apparatuses that usesemiconductor two-dimensional image detectors. These are configuredmainly with an X-ray source, a pressing panel for pressing the breast, atwo-dimensional X-ray image detector that holds the breast and images anintensity distribution of transmitted X-rays. Two-dimensional imagedetectors are produced by combining phosphor, which converts the X-raysto visible fluorescence, and a semiconductor two-dimensional imagedetector (see Japanese Patent Laid-Open No. 08-238233 for example).

Some mammography apparatuses use a grid to suppress scattered X-rays(see Japanese Patent Laid-Open No. 2005-013344 for example).

Furthermore, some apparatuses perform imaging with the X-ray image andan ultrasonic image of the breast under a same pressing condition. Forexample, infrared rays are used in a sensor that detects a position ofan ultrasonic probe in regard to these apparatuses. The breast ispressed in a same manner for obtaining the X-ray image and for obtainingthe ultrasonic image, and therefore as a result it is possible tocombine the ultrasonic image and the X-ray image (see Japanese PatentLaid-Open No. 2003-260046 for example).

Furthermore, techniques have been proposed (see Japanese PatentLaid-Open No. 09-505407 for example) in which a breast image is capturedby irradiating near infrared rays onto a breast through a breastcompressing panel and collecting transmitted light using optic fibers.

Further still, techniques have been proposed (for example, see SergioFantini et al, “Using Near-Infrared Light To Detect Breast Cancer,”Optics & Photonics News, November, 2003) in which a near infrared imageof a breast is obtained by causing a plurality of amplitude-modulatednear infrared rays to be incident on a single optic fiber thentransmitting this onto the breast and performing homodyne detection onthe transmitted near infrared rays.

In breast cancer diagnosis using mammography apparatuses,reproducibility of positioning between the imaging apparatus and thebreast is sometimes required for cytology and histology in a case wherea positive result is doubted or during postoperative observations overtime.

However, conventional mammography apparatuses do not have a positioningfunction.

On the other hand, although there are cases where near infrared imagesare effective in discovering tumorous cancer, which is a weak point forX-ray images, there is a problem in that it has not been possible toachieve a correspondence between the positions of the morbid portiondiscovered in the near infrared image and the X-ray image.

SUMMARY OF THE INVENTION

In light of the foregoing problems, the present invention provides amammography apparatus capable of reproducing breast positioning duringbreast X-ray imaging for example.

In one aspect of the present invention, a mammography apparatus forcapturing an X-ray image of a breast, comprises an X-ray source, adetector having a placement surface on which a breast is placed on aside opposing the X-ray source and that detects X-rays transmittedthrough the breast, wherein the detector is capable of detecting nearinfrared rays as well as being capable of detecting X-rays, an opticallytransparent or semitransparent pressing panel for pressing the breastthat is placed on the placement surface against the placement surface, atwo-dimensional near infrared ray source that is provided between theX-ray source and the pressing panel and arranged in a two-dimensionalshape in alignment with the pressing panel, and that is movable betweena first position in close contact with the pressing panel and a secondposition outside an X-ray image capture region, and a controller thatcarries out near infrared image capture using the two-dimensional nearinfrared ray source by causing the two-dimensional near infrared raysource to be in the first position, and causes the two-dimensional nearinfrared ray source to retract to the second position when carrying outX-ray image capture using the X-ray source.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1D are outlines of a mammography apparatus according to thepresent embodiment.

FIG. 2 is a diagram showing operation of a pressing panel when capturingan image for breast positioning.

FIGS. 3A and 3B are diagrams showing a structure of a two-dimensionaldetector.

FIGS. 4A and 4B are diagrams showing advancement and retraction of alaser diode matrix.

FIGS. 5A and 5B are diagrams showing a structure of a laser diodematrix.

FIG. 6 is a diagram showing one pixel of a semiconductor sensor.

FIG. 7 is a diagram in which pixels of the semiconductor sensor arearranged two-dimensionally.

FIG. 8 is a flowchart of a control process relating to X-ray breastimaging according to the present embodiment.

DESCRIPTION OF THE EMBODIMENTS

Various exemplary embodiments, features, and aspects of the presentinvention will be described in detail below with reference to thedrawings.

FIGS. 1A to 1D show outlines of a mammography apparatus according to thepresent embodiment.

FIG. 1B is a front view showing a state of the apparatus when capturinga CC (cranio-caudad) image of a breast 6, and is a diagram in which themammography apparatus is viewed from an examinee (patient). Arranged inorder from above are an X-ray source 1, a laser diode matrix 2, apressing panel 3, an X-ray grid 4, and a two-dimensional detector 5.FIG. 1A is a front view showing a state of the apparatus when capturingan MLO (medio-lateral oblique) image of the breast 6. A difference fromthe front view (when CC) of FIG. 1B is that a capture section is tilted.

Here, the two-dimensional detector 5 is a detector having a placementsurface on which the breast 6 is placed on a side opposing the X-raysource 1.

Description is given of a state of the apparatus at a time of obtainingan infrared image and a time of breast positioning shown in FIG. 1C. Inthis state, no X-rays are exposed from the X-ray source 1. The breast 6of an examinee placed on the placement surface of the two-dimensionaldetector 5 is pressed by the pressing panel 3 against the placementsurface. The laser diode matrix 2, which is a two-dimensional nearinfrared ray source arranged in a two-dimensional shape in alignmentwith the pressing panel 3, is provided above the pressing panel 3. Thelaser diode matrix 2 is configured to be movable between a firstposition in close contact with the pressing panel 3 and a secondposition outside an X-ray image capture region. A plurality of nearinfrared laser diodes are arranged in a matrix shape in the laser diodematrix 2. The pressing panel 3 is an optically transparent orsemitransparent material through which near infrared rays aretransmitted, and is a material through which X-rays are readilytransmitted, for example an acrylic or the like is appropriate.

The near infrared rays emitted from the near infrared laser diodes aretransmitted through the pressing panel 3 and proceed while undergoingattenuation and diffusion through the breast 6 to reach thetwo-dimensional detector 5. The X-ray grid 4 that does not transmit nearinfrared rays is retracted. The two-dimensional detector 5 includes atwo-dimensional semiconductor detector having sensitivity to visiblelight and near infrared ray. That is, the two-dimensional detector iscapable of detecting visible light and near infrared rays as well asbeing capable of detecting X-rays. A near infrared image of the breast 6is calculated based on an intensity distribution of light incident onthe two-dimensional detector 5. Here, the time of breast positioning isused because by displaying a near infrared image of the breast 6 in realtime, an imaging technician becomes capable of reproducing a positioningstate of the breast 6 based on vascular arrangement in the breast 6.

Description is given regarding differences between imaging for breastpositioning and imaging of near infrared images. All of these images areformed using near infrared rays. However, at a time of imaging forbreast positioning, increased speeds in image forming times are requiredfor the imaging technician to respond to changes in the breast settings.In this regard, time is required in imaging a breast spectroscopic imageusing near infrared laser diodes of multiple wavelengths in the laserdiode matrix 2.

Shortening the imaging times becomes possible by decimating rather thanlighting all the laser diodes incorporated in the laser diode matrix 2,thereby sacrificing image resolution to give priority to real timecapabilities.

Compared to imaging for breast positioning, imaging of near infraredimages is high resolution, and although it is spectroscopic, the imagingtimes become longer.

Next, description is given of a state of the apparatus shown in FIG. 1Dwhen capturing an X-ray image.

The X-ray image is captured after breast positioning is completed. Whenimaging for breast positioning and imaging of the near infrared imageare completed, the laser diode matrix 2 retracts from the X-ray imagecapture region.

On the other hand, the retracted X-ray grid 4, which is retracted at atime of imaging for breast positioning, is inserted above thetwo-dimensional detector 5. When the retraction of the laser diodematrix 2 and the insertion of the X-ray grid 4 are confirmed, X-rays areexposed.

In this regard, there is a correlation between a transmission amount ofnear infrared rays when imaging a near infrared image and a transmissionamount of X-rays. A positive correlation is known between breastthickness and mammary gland density and the amount of light that reachesthe two-dimensional detector 5. Using this relationship, it is possibleto determine an X-ray target, an X-ray filter, an X-ray tube current,and an imaging time when imaging an X-ray image. For example, in a casewhere the amount of light that reaches the detector is a specific valueor less, it is conceivable to use rhodium as the X-ray target ratherthan molybdenum. Furthermore, it is possible to increase the X-ray tubecurrent inversely proportional to the amount of light that reaches thedetector. In a case where the X-ray tube current cannot be increased dueto a limitation of the X-ray source, the imaging time is increased.

FIG. 2 indicates an operation of the pressing panel 3 when capturing animage for breast positioning and a timing of lighting the near infraredlaser diodes. Although the position setting of the breast and thecommencement of breast pressing are determined by the imaging technicianwhile confirming the safety of the patient, the lighting of the laserdiodes commences automatically when a predetermined pressing force orgreater is applied to the pressing panel 3. When capture of thepositioning image is completed, the lighting of the laser diodes stops.

Positioning images are displayed on a display device not shown in thediagrams. When the imaging technician judges that the positioning isappropriate, a transition is made to capturing a high resolution nearinfrared image. Images for judging the suitability of positioning caninclude displaying a difference image between a past image and a currentimage as well as being displayed in parallel to a previously capturedimage. A relative relationship between the images is important informing a difference image. A correlation coefficient of the two imagescan be calculated as an indicator of the relative relationship. Byperforming image shifting based on the correlation coefficient in adirection in which the correlation coefficient becomes larger, betterpositioning can be achieved.

FIGS. 3A and 3B are diagrams showing a structure of the two-dimensionaldetector 5.

When capturing an image for positioning and a near infrared image shownin FIG. 3A, the laser diode matrix 2 is arranged in close contact to anupper surface of the pressing panel 3. Hereinafter, an image forpositioning and a near infrared image are both indicated when referringto a near infrared image.

Near infrared rays that have been transmitted through the pressing panel3 and the breast 6 are incident on the two-dimensional detector 5. Thetwo-dimensional detector 5 has a protective panel 8, a wavelength filter9, an X-ray phosphor 10, a semiconductor sensor 11, and a sensorelevation mechanism 12.

The protective panel 8 protects the semiconductor sensor 11 duringbreast pressing. The protective panel 8 is a material having littleX-ray attenuation and through which near infrared rays are transmitted.For example, acrylic or reinforced glass can be used.

The wavelength filter 9 is a filter that transmits near infrared rays orrays of longer wavelengths than near infrared rays, and is a filmthrough which visible light and far infrared rays are not transmitted.

The X-ray phosphor 10 transmits near infrared rays, and generatesfluorescence with respect to incident X-rays. A CsI columnar crystal isappropriate as an example of the X-ray phosphor 10. Because it iscolumnar, diffusion of X-ray fluorescence and near infrared rays can bereduced.

A CMOS sensor for example can be used as the semiconductor sensor 11.Amorphous silicon sensors widely used in X-ray images cannot be usedsince they have no sensitivity to near infrared.

The sensor elevation mechanism 12 is a mechanism for adjusting thedistance between the lower surface of the protective panel 8 and theupper surface of the wavelength filter 9. By bringing the lower surfaceof the protective panel 8 and the upper surface of the wavelength filter9 close together, it is possible to reduce resolution deterioration innear infrared images.

When performing breast imaging, high resolution is demanded for theX-ray image, and for example a pixel pitch of 100 μm is necessary.

However, since X-ray images are still images, high speed image readoutis not required. On the other hand, a required resolution of nearinfrared images is approximately 1 to 3 mm. High speed image readout isnecessary for near infrared images.

Accordingly, with a pixel size of 100 μm, the structure of thesemiconductor sensor 11 is a structure capable of reading clusters of8×8 images, 16×16 images, or 32×32 pixels.

Furthermore, although X-ray images are formed at one time over theentire surface of the semiconductor sensor 11, near infrared images arelimited to a region of approximately 10 mm×10 mm with respect to asingle laser diode. Thus, when capturing a near infrared image, it isnecessary to perform partial (local) high speed reading at the same timeas cluster reading.

Furthermore, the semiconductor sensor 11 changes the image pickup regionin response to the resolution that is set when capturing a near infraredimage. A relative positional relationship between the laser diode matrix2 and the two-dimensional detector 5 can be known in advance bycalibration.

Next, description is given of a structure of FIG. 3B when capturing anX-ray image.

When capturing an X-ray image, the laser diode matrix 2 retracts and theX-ray grid 4 is inserted between the protective panel 8 and thewavelength filter 9. The X-ray grid 4 has an effect of reducing X-rayscattering. A gap between the protective panel 8 and the wavelengthfilter 9 is formed by downwardly shifting as a group the wavelengthfilter 9, the X-ray phosphor 10, and the semiconductor sensor 11 usingthe sensor elevation mechanism 12.

On the other hand, it is also possible to bring the wavelength filter 9in close contact with the lower surface of the protective panel 8 andinsert the X-ray grid 4 in a gap between the wavelength filter 9 and theX-ray phosphor 10. However, from a perspective of shielding thesemiconductor sensor 11, the foregoing method of inserting the X-raygrid 4 between the protective panel 8 and the wavelength filter 9 isbeneficial.

In this regard, a commonly known X-ray grid 4 is not a structure thattransmits near infrared rays. The X-ray grid 4 is a structure in whichwood or fiber or the like is sandwiched between lead foil.

However, it is possible to sandwich between the lead foil a fiber thattransmits near infrared rays.

When an X-ray grid 4 such as this capable of transmitting near infraredrays is used, the operations of inserting and retracting the grid becomeunnecessary, and optical shielding of the two-dimensional detector 5 iseasy.

FIGS. 4A and 4B show advancement and retraction of the laser diodematrix 2.

The pressing panel 3 is secured on a pressing panel support frame 13.The pressing panel support frame 13 is installed so as to be capable ofvertical movement on a support upper frame 7 of the imaging apparatus.

As shown in FIG. 4A, when capturing a near infrared image, the laserdiode matrix 2 slides on the pressing panel support frame 13 andadvances over the pressing panel 3. After advancement, the laser diodematrix 2 is brought in close contact with the pressing panel 3 using asuction or a pressure clamping mechanism (not shown in diagrams).

As shown in FIG. 4B, when capturing an X-ray image, the laser diodematrix 2 slides on the pressing panel support frame 13 to retract afterthe close contact is released.

FIGS. 5A and 5B show a structure of the laser diode matrix 2. The laserdiode matrix 2 is a two-layer structure.

First, description is given of an example in FIG. 5A.

In an upper portion, laser diodes 14 are arranged two-dimensionally, andin a lower portion, fibers are arranged two-dimensionally. The laserdiodes 14 and the fibers are made to correspond one to one, and adhered,pressed, or bound together.

In the example of FIG. 5B, four near infrared laser diodes 16 ofdifferent frequencies correspond to a single fiber as a group. By usingnear infrared rays of multiple frequencies, spectroscopy of the breast 6can be achieved.

In a case of achieving spectroscopy, four near infrared laser diodes 16having different frequencies are made to correspond to a single fiber inthe working example shown in FIG. 5B, but it is also possible to make alaser diode of each frequency corresponds to a single fiber.

FIG. 6 shows one pixel of the semiconductor sensor 11. Light incident ona photo diode 17 is converted to an electrical signal, a transfer switchsignal 18 becomes ON, and then the signal is output via a preamplifierby undergoing line selection.

FIG. 7 is a diagram in which pixels of FIG. 6 are arrangedtwo-dimensionally. Output of each pixel in an 8×8 array is selected by avertical shift register 24 and a horizontal shift register 25. Output ofa selected pixel is outputted via an amplifier 26. To capture an entirebreast image, a two-dimensional detector 5 is necessary having aneffective area of at least 20 cm×24 cm. This size can be achieved with asingle semiconductor sensor 11 using amorphous silicon, but for acrystal semiconductor such as CMOS, this size is currently impossible.On the other hand, when capturing a near infrared image, high speedlocal readouts are necessary. Accordingly, in the present embodiment,sensors of approximately 256×256 pixels are arranged in a tile shape toachieve an overall size of approximately 20 cm×24 cm.

Description is given regarding a function of the amplifier 26 of FIG. 7.

When reading out an X-ray image, pixels are selected one by one by thevertical shift register 24 and the horizontal shift register 25. Aconstant multiple setting is performed for a gain change signal 27, andtherefore a signal of the selected signal is amplified by the constantmultiple and output. When reading out the near infrared image, pixels ofa range surrounded by the dashed line are selected and output at thesame time. In the case of FIG. 7, 4×4 pixels are selected at the sametime. An added signal of selected pixel signals is amplified by theamplifier 26. Gain change is performed using the gain change signal 27during amplification. A signal of a frequency approximating a frequencyof an intensity modulated signal of the laser diodes is used as the gainchange signal 27.

Spectroscopic imaging methods using near infrared rays are described indetail in the above-mentioned Sergio Fantini et al, “Using Near-InfraredLight To Detect Breast Cancer,” Optics & Photonics News, November, 2003.Here, simple description is given of a method in which near infraredrays of four wavelengths are used.

Laser diode lights of 690 nm, 750 nm, 788 nm, and 856 nm are used forthe four wavelengths. The light of the four wavelengths undergoesamplitude modulation at 70.45 MHz, 70.20 MHz, 69.80 MHz, and 69.5 MHzrespectively.

Amplitude modulated light is made incident on the breast 6 clusteredinto a single fiber as shown in the structure shown in FIG. 5B. Lightthat is transmitted through the breast 6 is incident on a single regionof cluster reading pixels 23 shown in FIG. 7. Incident signals areamplified by the amplifier 26, and a 70 MHz signal is used in the gainchange signal 27 when amplifying.

Signals of four wavelengths are separated from a gain change outputsignal 28 such that four near infrared images can be formed.

Spectroscopy is created by combining the four images using imageprocessing. This system is referred to as frequency domain opticalmammography, but the near infrared images used in the present inventionare not limited to this system, and configurations according to thepresent invention can be used in other systems also.

Description is given regarding a case where differences occur from thefrequency domain system disclosed in Sergio Fantini et al, “UsingNear-Infrared Light To Detect Breast Cancer,” Optics & Photonics News,November, 2003. When collecting near infrared rays, in the foregoingdescription, only a single location of cluster reading pixels 23 areread out with respect to emitted rays of the single laser diode (in thecase of FIG. 5B, four laser diodes forming a single group).

However, when consideration is given to a case where diffusioninformation of the near infrared rays also includes information, it isconceivable to read out multiple cluster reading pixels 23.

For example, when reading out four cluster reading pixels 23, reading isperformed serially (successively), and therefore phase differences occurin the gain change.

Accordingly, it is necessary to give consideration that there are phasedifferences between the four pixels when extracting beats using homodynedetection. Note however that the phase differences of the four clusterreading images are already known since these correspond to a read-infrequency of the semiconductor sensor.

Description is given regarding an image correction method. Inconventional two-dimensional detectors 5 specialized for X-ray images, athin aluminum sheet is used instead of the wavelength filter 9. In thiscase, there is no risk that visible light, near infrared rays, orinfrared rays will be incident. However, depending on characteristics ofthe wavelength filter 9, there is a risk that small amounts of visiblelight, near infrared rays, or infrared rays will be incident on thesemiconductor sensor 11 when near infrared rays are not being emittedfrom the laser diodes.

Furthermore, the structure is complicated compared to the conventionaltwo-dimensional detector 5 specialized for X-ray images, and thereforethere is also a risk that the above-mentioned light will be incident inminute amounts. These lights become offsets and reduce the contrast inimages.

Consequently, before capturing the near infrared image of FIG. 3A andcapturing the X-ray image, black images (dark images) are capturedrespectively and subtracted from the acquired images respectively.Furthermore, shading correction is possible by capturing a white imagewhen capturing the near infrared image and when capturing the X-rayimage respectively and dividing these by the acquired images. The whiteimage is an image in a case where the laser diodes or X-rays are emittedwhile there is no subject.

Finally, description is given using a flowchart of FIG. 8 of a controlprocess relating to X-ray breast imaging according to the presentembodiment.

Acquisition of a correction image is carried out at S0 before imaging ofa patient. Correction images are acquired immediately prior to patientimaging giving consideration to temperature drift of the two-dimensionaldetector 5.

Imaging of the patient commences at S1. At S2, the technician performsinitial setting of the breast 6 of the patient on an imaging platform.At S3, the laser diode matrix 2 advances to a first position in closecontact with the pressing panel 3, and the X-ray grid 4 retracts. At S4,the pressing panel 3 is lowered by operation of the technician, and whenpressure is detected at S5, light is emitted from the laser diodes at S6and imaging commences.

When exposure from each laser diode and transmitted light detection iscompleted at S7, a comparison is carried out with a past near infraredimage at S8. The comparison may also involve displaying a differenceimage.

At S9, a confirmation of position reproducibility is carried out. Ifreproducibility is confirmed, a high precision near infrared image iscaptured at S10.

At S11, the laser diode matrix 2 retracts to a second position outsidean X-ray image capture region, and the X-ray grid 4 is inserted. At S12,X-ray exposure is carried out and at S13, X-ray image acquisition iscarried out. The near infrared image and the X-ray image are capturedunder identical conditions, and therefore at S14 it is possible to carryout image processing overlaying the images without needing to performgeometrical conversions. The X-ray image displayed in black and whiteand the near infrared image displayed in color can be overlaid. At S15,imaging is completed.

With the present invention, reproduction of breast settings (capturemethod) is possible in X-ray breast imaging.

This enables near infrared images and X-ray images to be captured underidentical conditions.

Furthermore, by displaying an overlay of the near infrared image and theX-ray image, an overlay of calcified cancer and tumorous cancer can becarried out with excellent accuracy.

Furthermore, it becomes possible to estimate an appropriate imaging dosewhen transitioning from a near infrared image to X-ray imaging.

Further still, images having excellent contrast can be achieved bycapturing in advance images for correction of the near infrared imageand the X-ray image respectively from the same sensor.

Other Embodiments

Aspects of the present invention can also be realized by a computer of asystem or apparatus (or devices such as a CPU or MPU) that reads out andexecutes a program recorded on a memory device to perform the functionsof the above-described embodiment(s), and by a method, the steps ofwhich are performed by a computer of a system or apparatus by, forexample, reading out and executing a program recorded on a memory deviceto perform the functions of the above-described embodiment(s). For thispurpose, the program is provided to the computer for example via anetwork or from a recording medium of various types serving as thememory device (e.g., computer-readable medium).

An embodiment of the present invention can provide a mammographyapparatus for capturing an X-ray image of a breast, comprising: an X-raysource; a detector having a placement surface on which a breast isplaced on a side opposing the X-ray source and that detects X-raystransmitted through the breast, wherein the detector is capable ofdetecting near infrared rays as well as being capable of detectingX-rays; an optically transparent or semitransparent pressing panel forpressing the breast that is placed on the placement surface against theplacement surface; a two-dimensional near infrared ray source that isprovided between the X-ray source and the pressing panel and arranged ina two-dimensional shape in alignment with the pressing panel, and thatis movable between a first position in close contact with the pressingpanel and a second position outside an X-ray image capture region, and acontroller that carries out near infrared image capture using thetwo-dimensional near infrared ray source by causing the two-dimensionalnear infrared ray source to be in the first position, and causes thetwo-dimensional near infrared ray source to retract to the secondposition when carrying out X-ray image capture using the X-ray source.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2008-285707, filed Nov. 6, 2008, which is hereby incorporated byreference herein in its entirety.

1. A mammography apparatus for capturing an image of a breast,comprising: an X-ray source; a detector having a placement surface onwhich a breast is placed, wherein the placement surface opposes theX-ray source, and wherein the detector is configured to detect X-raysand near infrared rays transmitted through the breast; a pressing panelfor pressing the breast that is placed on the placement surface againstthe placement surface and for transmitting X-rays and near infrared raystherethrough; a two-dimensional near infrared ray source for providingnear infrared rays and is configured: to be provided between the X-raysource and the pressing panel, and to be movable between a firstposition in which the two-dimensional near infrared ray source is incontact with the pressing panel and a second position outside an X-rayimage capture region, and a controller configured to carry out nearinfrared image capture using the two-dimensional near infrared raysource by moving the two-dimensional near infrared ray source to thefirst position, and configured to carry out X-ray image capture usingthe X-ray source by moving the two-dimensional near infrared ray sourceto the second position.
 2. The mammography apparatus according to claim1, wherein the pressing panel comprises optically transparent orsemitransparent material, and wherein the two-dimensional near infraredray source is configured to be in a two-dimensional shape in alignmentwith the pressing panel.
 3. The mammography apparatus according to claim1, wherein the two-dimensional near infrared ray source is configured tobe brought into contact with the pressing panel by using a suction or apressure clamping mechanism.
 4. The mammography apparatus according toclaim 1, wherein the detector comprises: a wavelength filter configuredto transmit near infrared rays or rays of longer wavelengths than nearinfrared rays, a phosphor configured to transmit near infrared rays, andto generate fluorescence with respect to incident X-rays, and asemiconductor sensor configured to sense near infrared rays.
 5. Themammography apparatus according to claim 1, further comprising: an imageprocessor that overlays a captured near infrared image and an X-rayimage.
 6. The mammography apparatus according to claim 1, wherein thecontroller is further configured to carry out decimated lighting of thetwo-dimensional near infrared ray source when carrying out capture ofthe near infrared image for breast positioning.
 7. The mammographyapparatus according to claim 1, further comprising a correctorconfigured to carry out correction of the captured near infrared imageand X-ray image using a black image and a white image by capturing ablack image and a white image before capturing the near infrared imageand capturing the X-ray image respectively.
 8. The mammography apparatusaccording to claim 4, wherein the semiconductor sensor is a CMOS sensor.9. The mammography apparatus according to claim 4, wherein the detectorfurther comprises a protective panel and a sensor elevation mechanism,wherein the sensor elevation mechanism is a mechanism for adjusting thedistance between the protective panel and the wavelength filter.
 10. Themammography apparatus according to claim 9, wherein the controller isconfigured to retract the two-dimensional near infrared ray source andto insert an X-ray grid 4 between the protective panel and thewavelength filter, when capturing an X-ray image.
 11. The mammographyapparatus according to claim 1, further comprising an X-ray gridconfigured to transmit near infrared rays.
 12. The mammography apparatusaccording to claim 1, wherein the laser matrix comprises a first portionof laser diodes arranged two-dimensionally and a second portion offibers arranged two-dimensionally, wherein the diodes and the fiberscorrespond on a one to one basis or one fiber corresponds to a group ofdiodes of different frequencies.
 13. A method for capturing an image ofa breast, comprising: detecting X-rays and near infrared raystransmitted through a breast which has been placed on a placementsurface of a detector; pressing, with a pressing panel, said breastagainst the placement surface; moving a two-dimensional near infraredray source between a first position in which the two-dimensional nearinfrared ray source is in contact with the pressing panel and a secondposition outside an X-ray image capture region, and carrying out nearinfrared image capture by moving the two-dimensional near infrared raysource to the first position, and carrying out X-ray image capture bymoving the two-dimensional near infrared ray source to the secondposition.
 14. A program which, when executed by a computer, causes thecomputer to carry out the method of claim
 13. 15. A storage mediumstoring the computer program according to claim 14.